Azo-dyestuffs



Patented Sept. 24, 1935 I UNITED STATES PATENT OFFICE AVZO-DYVESTUFFS n N. Y., a corporation of Delaware No Drawing. Application November 26, 1934, Serial No. 754,912. In Germany December 1,

4 Claims.

The present invention relates to azo-dyestuffs;

more particularly it relates to dyestuffs of the following general formula:

wherein R stands for a radical of the benzene or naphthalene series, R1 for hydrogen or methyl,

R2 for a radical of the benzene, naphthalene or diphenyl series, and wherein at least one of the radicals R and R2 contains at least one substituent of the group consistingof sulfonic acid and carboxylic acid groups.

We have found that azo-dyestuffs of very good fastness properties are obtainable by combining diazotized bases with pyrazolones of the following constitution:

wherein R1 stands for hydrogen or alkyl and R for an aryl radical, the dyestuffs components being chosen that the dyestuffs contain at least one group lending solubility in water, such as, for instance, the sulfonic acid or carboxylic acid group.

The new dyestuffs dye wool from an acid bath yellow to red tints of very good fastness properties. In comparison with the analogous pyrazolone-azo-dyestuffs, which are substituted in 3- position of the pyrazolone nucleus by a methyl, carboxylic acid or carboxylic acid ester group, the dyestuffs of the present invention are distinguished by an enhanced fastness to washing and to fulling. When compared with the amdyestuffs from 1,3-diphenyl-5-pyrazolone, described'in Berichte der Deutschen Chemischen Gesellschaft, vol. 35, (1902), pages 928-929, and in German Patent No. 253,287, the new dyestuffs possess a better fastness to Washing and to light.

By using dyestufi-components which contain groups capable of being chromed, such as, for

instance, a hydroxyl, carboxyl or arylsulfamino' group standing in ortho-position to the diazo group of the base applied, or the grouping of a carboxyl or arylsulfamino group standing in ortho-position to a hydroxyl group, dyeings on wool are obtained which, after being treated with agents yielding chromium, are distinguished by properties of fastness which surpass those of the unchromed dyestuffs.

The pyrazolones used for the preparation of the dyestuffs may be obtained by condensing aroyl acetic esters of the formula:

R-COCH2COOR with hydrazines of the formula:

R1NHNH2 wherein R and R1 have the same meaning as in the above formula for the pyrazolones, and wherein R" stands for an alkyl radical, to form the hydrazones and then closing the pyrazolone ring.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto; the parts are by weight:

(1) 17.3 parts of ortho-aniline-sulfonic acid are dissolved in 300 parts of water and 25 parts of hydrochloric acid of 20 B. and diazotized with 6.9 parts of sodium-nitrite in the form of a 2 N. solution. This diazo-solution is introduced into a solution of 20.4 parts of 3-(lcarboxyphenyl) 5-pyrazolone which has been rendered alkaline by means of sodium carbonate. When the coupling is finished, the dyestuif is salted out by means of sodium chloride, filtered and dried. It corresponds to the following formula:

803E G-OH and dyes wool from an acid bath red tints of very 55 good fastness to washing and to light. By aftertreating the dyeing with chromium salts the fastness properties may still be enhanced.

(3) By using in Example I, instead of orthowise good fastness properties. The following table indicates a number of further dyestuffs which are obtainable according to the present invention:

Diazotizing component Coupling component Tint on wool l 1 4-chlor0aniline-Z-sulfonic acid 3-(4-cl1lorophenyl)-5-pyraz0lone Yellow. 2 4-nitro-2-aminophenol-(i-sullonic acid 3-(4-methoxyphcnyl)-5-pyrazol0ne.. Brownish-red. 3 l-amino2'carboxybenzenei-sulfonic ac 3-(a-naphthy1)-5-pyrazo1one.. Redd1sh-yell0w 4 4-toluidine-3-sultonic acid 3-(4-carboxyphenyl)-5-pyrazolone. Yellow. 5 4-chloro-2-aminophenol-6-sulfonic acid." do Red. 6 nitro-l-amino-2-naphthol-4-sulfonic acid. do r. Bluish-red. 7 sulfanilic acid 1-methyl-3-pheny1-5-pyrazolone Yellow 8 3-nitro-5-an1ino-Z-hydroxy-l-benzoic acid- 1-metl1yl-3-(4-methylphenyl)-5-pyrazolone Browmsh-orange. 9 l-amino-2-naphthol-4-sulfonic acid l-methy -(fipht y -py Red. 10 metanilic acid l-methyl-3-(4-carb0xyphenyl)-5-pyrazolon Greenish-yellow. 11 4,4-diaminodiphenyl-3,3-disulfonic do Red. 15 12 6-nitro-2-aminopnenol-4-sulfonic acid l .do Brownish-red.

aniline-sulfonic acid, 21.? parts of Z-amino-l- We claim: sulfo-l-benzoic acid and, as coupling component, 1. The azo-dyestuffs of the following general 17.4 parts of 1-methyl-3-phenyl-5-pyrazolone in formula: a solution which has been rendered alkaline by 5 means of caustic soda and working up in the N manner described in Example 1 there is obtained after salting out, filtering and drying the dye- R L g N N R stud of the following formula: T T 1 wherein R stands for a radical of the benzene or CH3 naphthalene series, R1 for hydrogen or methyl, R2 for a radical of the benzene, naphthalene or COOH diphenyl series, and wherein at least one of the N radicals R and R2 contains at least one substitu- It gHNzN ent of the group consisting of sulphonic acid and carboxylic acid groups, dyeing wool from an acid SOQH bath yellow to red tints of very good fastness properties.

2. The azo-dyestuff of the following formula: which dyes wool from an acid bath yellow tints H of good fastness properties. By after-treating IlI the dyeing with chromium salts, the fast-ness SOJH properties may be enhanced.

(4) 22.3 parts of Z-naphthylamine-1-sulfonio acid are dissolved in a sodium carbonate solution, and 6.9 parts of sodium nitrite are added in the form of a 2 l. solution. The clear solution is diazotized by introducingit into a mixture of 20 parts of raw hydrochloric acid and ice. The

diazo solution is then run into a solution of 21.8

parts of 1-methyl-3-(4'-carboxyphenyl)-5-pyrazolone which has been rendered alkaline by means of sodium carbonate. When the coupling is finished, the dyestuff is salted out, filtered with suction and dried. It corresponds to the following formula:

CIJHB N dyeing wool from an acid bath greenish-yellow tints of very good fastness to washing and to light.

3. The azo-dyestuff of the following formula:

yielding on wool, when after-chromed, a red dye- SOzH ing of very good fastness to washing and to light.

4. The azo-dyestuff of the following formula:

SOaH 

